O Moser1,2, M L Eckstein1,2, A Mueller3,4, P Birnbaumer3, F Aberer5, G Koehler5, C Sourij5, H Kojzar5, P Holler4, H Simi4, P Pferschy5, P Dietz6,7, R M Bracken1,2, P Hofmann3, H Sourij5. 1. Diabetes Research Group, Medical School, Swansea University, Swansea, UK. 2. Applied Sport, Technology, Exercise and Medicine Research Centre (A-STEM), College of Engineering, Swansea University, Swansea, UK. 3. Exercise Physiology, Training and Training Therapy Research Group, Institute of Sports Science, Medical University of Graz, Graz, Austria. 4. Sport Science Laboratory, FH Joanneum University of Applied Science, Bad Gleichenberg, Austria. 5. Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. 6. Department of Physical Activity and Public Health, Institute of Sports Science, Medical University of Graz, Graz, Austria. 7. Institute of Occupational, Social and Environmental Medicine, University Medical Centre of the University of Mainz, Mainz, Germany.
Abstract
AIMS: To evaluate the sensor performance of the FreeStyle Libre intermittently viewed continuous glucose monitoring system using reference blood glucose levels during moderate-intensity exercise while on either full or reduced basal insulin dose in people with Type 1 diabetes. METHODS:Ten participants with Type 1 diabetes [four women, mean ± sd age 31.4 ± 9.0 years, BMI 25.5±3.8 kg/m2 , HbA1c 55±7 mmol/mol (7.2±0.6%)] exercised on a cycle ergometer for 55 min at a moderate intensity for 5 consecutive days at the clinical research facility, while receiving either their usual or a 75% basal insulin dose. After a 4-week washout period, participants performed the second exercise period having switched to the alternative basal insulin dose. During exercise, reference capillary blood glucose values were analysed using the fully enzymatic-amperometric method and compared with the interstitial glucose values obtained. Intermittently viewed continuous glucose monitoring accuracy was analysed according to median (interquartile range) absolute relative difference, and Clarke error grid and Bland-Altman analysis for overall glucose levels during exercise, stratified by glycaemic range and basal insulin dosing scheme (P<0.05). RESULTS: A total of 845 glucose values were available during exercise to evaluate intermittently viewed continuous glucose monitoring sensor performance. The median (interquartile range) absolute relative difference between the reference values and those obtained by the sensor across the glycaemic range overall was 22 (13.9-29.7)%, and was 36.3 (24.2-45.2)% during hypoglycaemia, 22.8 (14.6-30.6)% during euglycaemia and 15.4 (9-21)% during hyperglycaemia. Usual basal insulin dose was associated with a worse sensor performance during exercise compared with the reduced (75%) basal insulin dose [median (interquartile range) absolute relative difference: 23.7 (17.2-30.7)% vs 20.5 (12-28.1)%; P<0.001). CONCLUSIONS: The intermittently viewed continuous glucose monitoring sensor showed diminished accuracy during exercise. Absolute glucose readings derived from the sensor should be used cautiously and need confirmation by additional finger-prick blood glucose measurements.
RCT Entities:
AIMS: To evaluate the sensor performance of the FreeStyle Libre intermittently viewed continuous glucose monitoring system using reference blood glucose levels during moderate-intensity exercise while on either full or reduced basal insulin dose in people with Type 1 diabetes. METHODS: Ten participants with Type 1 diabetes [four women, mean ± sd age 31.4 ± 9.0 years, BMI 25.5±3.8 kg/m2 , HbA1c 55±7 mmol/mol (7.2±0.6%)] exercised on a cycle ergometer for 55 min at a moderate intensity for 5 consecutive days at the clinical research facility, while receiving either their usual or a 75% basal insulin dose. After a 4-week washout period, participants performed the second exercise period having switched to the alternative basal insulin dose. During exercise, reference capillary blood glucose values were analysed using the fully enzymatic-amperometric method and compared with the interstitial glucose values obtained. Intermittently viewed continuous glucose monitoring accuracy was analysed according to median (interquartile range) absolute relative difference, and Clarke error grid and Bland-Altman analysis for overall glucose levels during exercise, stratified by glycaemic range and basal insulin dosing scheme (P<0.05). RESULTS: A total of 845 glucose values were available during exercise to evaluate intermittently viewed continuous glucose monitoring sensor performance. The median (interquartile range) absolute relative difference between the reference values and those obtained by the sensor across the glycaemic range overall was 22 (13.9-29.7)%, and was 36.3 (24.2-45.2)% during hypoglycaemia, 22.8 (14.6-30.6)% during euglycaemia and 15.4 (9-21)% during hyperglycaemia. Usual basal insulin dose was associated with a worse sensor performance during exercise compared with the reduced (75%) basal insulin dose [median (interquartile range) absolute relative difference: 23.7 (17.2-30.7)% vs 20.5 (12-28.1)%; P<0.001). CONCLUSIONS: The intermittently viewed continuous glucose monitoring sensor showed diminished accuracy during exercise. Absolute glucose readings derived from the sensor should be used cautiously and need confirmation by additional finger-prick blood glucose measurements.
Authors: Othmar Moser; Max L Eckstein; Alexander Mueller; Philipp Birnbaumer; Felix Aberer; Gerd Koehler; Caren Sourij; Harald Kojzar; Peter Pferschy; Pavel Dietz; Richard M Bracken; Peter Hofmann; Harald Sourij Journal: Nutrients Date: 2019-06-06 Impact factor: 5.717
Authors: Othmar Moser; Max L Eckstein; Olivia McCarthy; Rachel Deere; Jason Pitt; David M Williams; Jennifer Hayes; Harald Sourij; Stephen C Bain; Richard M Bracken Journal: Diabetes Obes Metab Date: 2019-08-05 Impact factor: 6.577
Authors: Othmar Moser; Norbert Tripolt; Peter Pferschy; Anna Obermayer; Harald Kojzar; Alexander Mueller; Hakan Yildirim; Caren Sourij; Max Eckstein; Harald Sourij Journal: Biosensors (Basel) Date: 2021-01-15
Authors: Othmar Moser; Michael C Riddell; Max L Eckstein; Peter Adolfsson; Rémi Rabasa-Lhoret; Louisa van den Boom; Pieter Gillard; Kirsten Nørgaard; Nick S Oliver; Dessi P Zaharieva; Tadej Battelino; Carine de Beaufort; Richard M Bergenstal; Bruce Buckingham; Eda Cengiz; Asma Deeb; Tim Heise; Simon Heller; Aaron J Kowalski; Lalantha Leelarathna; Chantal Mathieu; Christoph Stettler; Martin Tauschmann; Hood Thabit; Emma G Wilmot; Harald Sourij; Carmel E Smart; Peter G Jacobs; Richard M Bracken; Julia K Mader Journal: Pediatr Diabetes Date: 2020-10-13 Impact factor: 4.866
Authors: Max L Eckstein; Benjamin Weilguni; Martin Tauschmann; Rebecca T Zimmer; Faisal Aziz; Harald Sourij; Othmar Moser Journal: J Clin Med Date: 2021-05-31 Impact factor: 4.241
Authors: Florian H Guillot; Peter G Jacobs; Leah M Wilson; Joseph El Youssef; Virginia B Gabo; Deborah L Branigan; Nichole S Tyler; Katrina Ramsey; Michael C Riddell; Jessica R Castle Journal: Biosensors (Basel) Date: 2020-09-29
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